Spec tests!

Work in progress. **Waiting for some feedback and testing from others before merging.**

An initial stab at spec testing for our Puppet Composer module. This uses `rspec-puppet`, `puppetlabs_spec_helper`, and Travis CI to perform spec testing. I am using RVM in my environment and specify a gemset in the `Gemfile`. I'd encourage others to use RVM or rbenv to setup a sandboxed environment.

For Travis CI to work properly, @tPl0ch will need to setup the repository there. You can see an example at https://travis-ci.org/andyshinn/puppet-composer.

To run the spec tests:

* `bundle install` to get the needed gems.
* `rake spec` to run the tests.

Feedback before merging?